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Mississippian-like rugose corals from a Bashkirian biostrome in the Tindouf Basin, S. Morocco Mississippian-like rugose corals from a Bashkirian biostrome in the Tindouf Basin

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A rich rugose coral assemblage has been recorded from a biostrome at the top of the Djebel Ouarkziz Fm. in the Tindouf Basin, S. Morocco. It is composed of 10 genera and 14 species, of which 5 are new: Dibunophyllum bipartitum, Arachnolasma sp., Palaeosmilia murchisoni, Palaeosmilia ressoti, Palastraea regia, Siphonodendron tindoufense sp. nov., Siphonodendron ouarkzizense sp. nov., Diphyphyllum maximum, Axophyllum moroccoense sp. nov., Gangamophyllum sp., Axoclisia sahariense sp. nov., Axoclisia cf. coronata, Actinocyathus sarytschevae and Actinocyathus mariae sp. nov. It represents essentially a Mississippian-type coral fauna but with some evolved species. However, its age, as determined by foraminifers, is early Bashkirian (Early Pennsylvanian). The presence of Mississippian-like corals in the Bashkirian indicates that the epicontinental basins in northern Gondwana (Saharan basins) were a refuge for coral faunas during the late Serpukhovian extinction event. The persistence of the Mississippian assemblages in the Bashkirian from northern Gondwana was probably due to a combination of warm waters and tectonic stability. The coral assemblage from the Tindouf biostrome is similar to those
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... However, for those taxa identified previously from these sections, only brief comments are recorded to highlight diagnostic properties or unusual features. Comparisons have been made with rugose coral faunas documented from other Serpukhovian and younger locations in Morocco (Rodríguez et al. 2013) and Algeria (Semenoff-Tian-Chansky 1974, 1985Aretz 2011;Atif et al. 2016). ...
... Dibunophyllum bipartitum (McCoy, 1849) ( Fig. 4:5)-Only one fragmentary specimen has been recorded. This species has a long stratigraphic record, being already recorded in the lower Bashkirian from Tindouf Basin (Rodríguez et al. 2013). Thomson and Nicholson, 1876 (Fig. 4:6-7)-Only a single specimen recorded. ...
... The microstructure of the septa is fibrous; consequently, it is closer to H. parvicarinatum, despite the fact that it does not show carinae in the dissepimentarium. Rodríguez et al., 2013 (see details in the assemblage from Tirhela at a similar stratigraphical level)-Three specimens show a very poor preservation, but their features and size fit well with the species from the Tindouf Basin (Rodríguez et al. 2013). two Bashkirian species (S. tindoufense and S. ouarkzizense), recorded in the Tindouf Basin (Rodríguez et al. 2013) and share with them the main diagnostic features, mostly flat tabulae and discontinuous axial columella. ...
Article
The Carboniferous outcrops from Adarouch (central Morocco) are composed of siliciclastic and carbonate rocks, and the latter have yielded abundant fossils. The upper part of the marine succession in the Idmarrach Formation and its laterally equivalent Tirhela Formation belong to the Bashkirian. More recent investigations of poorly preserved coral assemblages from the upper part of Idmarrach 2 section and the upper part of the Tirhela Formation are here described. The assemblage from the upper Idmarrach Formation comprises several typical Mississippian taxa, such as Aulophyllum fungites , Dibunophyllum bipartitum , Koninckophyllum interruptum, Siphonodendron scaleberense and Lithostrotion decipiens, and some highly evolved forms previously undescribed of Mississippian genera such as Haplolasma sp., Arachnolasma sp., Siphonodendron sp., Diphyphyllum sp., Solenodendron sp., Clisiophyllum sp. and a new species Corwenia tirhelensis sp. nov. In addition, an undetermined petalaxid has been also recorded. Similarly, the assemblage from near the top of the Tirhela Formation yielded some species regarded usually as Mississippian, such as Palaeosmilia murchisoni and Lithostrotion decipiens . We also identified the long-ranging tabulate Syringopora sp., Corwenia tirhelensis sp. nov., and a single species of the fasciculate rugosan, Siphonodendron tindoufense, previously described from Bashkirian rocks in the Tindouf Basin (southern Morocco). The presence of the latter taxon in both the Idmarrach and Tirhela sections implies a communication between the Adarouch region and the Saharan basins. The occurrence of S. tindoufense at the approximately same stratigraphic level in Tindouf, Taoudenni, Reggan-Ahnet and Adarouch, demonstrates its important regional stratigraphic value in North Africa.
... Bamber et al. (2017) described three zones for these corals from Tindouf Basin, which are the Siphonodendron Zone, Kizilia Zone and Actinocyathus Zone approximately corresponding to the late Asbian, Brigantian and Serpukhovian, respectively. Similar to the Adarouch Basin, rich rugose corals also occur in the early Bashkirian, which are characterized by Actinocyathus, Arachnolasma, Axoclisia, Axophyllum, Dibunophyllum, Diphyphyllum, Gangamophyllum, Palaeosmilia, Palastraea and Siphonodendron (Rodríguez et al. 2013b). The composition of the Moroccan corals shows close similarities to that of the Western Palaeotethys (Rodríguez et al. 2013b(Rodríguez et al. , 2016a. ...
... Similar to the Adarouch Basin, rich rugose corals also occur in the early Bashkirian, which are characterized by Actinocyathus, Arachnolasma, Axoclisia, Axophyllum, Dibunophyllum, Diphyphyllum, Gangamophyllum, Palaeosmilia, Palastraea and Siphonodendron (Rodríguez et al. 2013b). The composition of the Moroccan corals shows close similarities to that of the Western Palaeotethys (Rodríguez et al. 2013b(Rodríguez et al. , 2016a. ...
... The other is the compositional changeover event of rugose coral assemblages during the mid-Carboniferous (Serpukhovian-Bashkirian boundary), which is represented by the disappearance of many Mississippian rugose corals, such as large dissepimented taxa with complex axial structures, and the appearance of typical Pennsylvanian taxa characterized by compound rugose taxa belonging to the Petalaxidae, Geyerophyllidae and Waagenophyllidae (Kossovaya 1996;Wang et al. 2006Wang et al. , 2013. However, some columellate large dissepimented genera survived, such as Dibunophyllum, Corwenia, Bothrophyllum, Clisiophyllum, Arachnolasma and Aulophyllum, as well as the non-columellate large dissepimented Palaeosmilia (Kossovaya 1996;Fedorowski et al. 2012;Rodríguez et al. 2013bRodríguez et al. , 2016b. This changeover event is associated with the global regressive event, resulting from an episode of enhanced glaciation in Gondwana (Grossman et al. 2008;Wang et al. 2013;Chen et al. 2016). ...
Article
Rugose corals are one of the major fossil groups in shallow-water environments. They played an important role in dividing and correlating Carboniferous strata during the last century, when regional biostratigraphic schemes were established and may be useful for long-distance correlation. Carboniferous rugose corals document two evolutionary events. One is the Tournaisian recovery event, with abundant occurrences of typical Carboniferous rugose corals such as columellate taxa and a significant diversification of large, dissepimented corals. The other is the changeover of rugose coral composition at the mid-Carboniferous boundary, which is represented by the disappearance of many large dissepimented taxa with complex axial structures and the appearance of typical Pennsylvanian taxa characterized by compound rugose taxa. The biostratigraphic scales for rugose corals show a finer temporal resolution in the Mississippian than in the Pennsylvanian, which was probably caused by the Late Paleozoic Ice Age that resulted in glacial-eustatic changes and a lack of continuous Pennsylvanian carbonate strata. The Pennsylvanian rugose corals are totally missing in the Cimmerian Continent. High-resolution biostratigraphy of rugose corals has so far only achieved in few regions for the Mississippian time scale. In most regions, more detailed taxonomic works and precise correlations between different fossil groups are needed.
... The genus Siphonodendron originated in the late Moliniacian (early Viséan) and evolved especially rapidly, reaching peak diversity in the late Viséan. Siphonodendron colonies contributed to the formation of biostromes in the middle Viséan to Serpukhovian and to bioherms in the late Viséan and Serpukhovian (e.g., Herbig, 2003b, 2008), though a few records can extend into the early Bashkirian in North Africa which were also recognized as renewal coral faunas survived from the mid-Carboniferous extinction event ( Rodríguez et al., 2013). ...
... In consequence, the tropical reef belt expanded polewards. The Yamansu biostrome might be one such example in the Northern Hemisphere and the examples from the Sahara ( Rodríguez et al., 2013) for the Southern Hemisphere. Fur- thermore, the high relative sea-level of the late Viséan resulted in many expanded carbonate-dominated shelf systems, which favored the for- mation of biostromes (e.g., Aretz and Chevalier, 2007;Aretz, 2010). ...
Article
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For the first time, a Mississippian coral biostrome is described from the Eastern Tianshan, Xinjiang Province, Northwest China. Rugose corals and foraminifers show that the biostrome developed during the late Viséan in one of the rare carbonate levels in the mainly volcanic-siliciclastic succession of the Yamansu Formation. A single fasciculate coral, Siphonodendron irregulare, dominates (>80%) this biostrome. Of the 22 coral genera found in the Yamansu Formation, 5 colonial and 6 solitary dissepimented corals are recorded in the biostrome. The biostrome can be divided vertically into two parts. In the main thick part dominate large patches of in situ Siphonodendron irregulare colonies. In the thinner uppermost part, Siphonodendron irregulare and Lithostrotion formed locally isolated small patches in a capping bed. The initial growth of the coral patches was related to slight topographic irregularities in the underlying volcano-sedimentary rocks. Siphonodendron irregulare appears to have been the best adapted species to the environmental pressures in the unstable tectono-sedimentary environment of the Yamansu Formation. It flourished and outnumbered the other corals when volcanic activity ceased and carbonate production became active for a short time. The development of the Siphonodendron biostrome ceased due to increases in sea-level and volcanic activity. Compared to Siphonodendron biostromes in the western and eastern Paleotethys, the Siphonodendron biostrome in Yamansu is unique for having developed in an island arc setting. To date, the Yamansu biostrome is the only documented coral bioconstruction at similar latitudes in the Central Asian Orogenic Belt (CAOB). Formation of this coral biostrome was controlled by extrinsic factors, such as changes in global climate and ocean currents, and intrinsic factors, such as the pioneering nature of the fast-growing Siphonodendron irregulare. Both sets of factors are responsible for the expansion of the tropical reef belt into previously more temperate environments.
... Four typically Viséan genera: Dibunophyllum Thomson and Nicholson, 1876;Rozkowskia Fedorowski, 1970;Spirophyllum Fedorowski, 1970;and Zakowia Fedorowski, 1971 are described here from Bashkirian strata. The occurrence of Dibunophyllum in the early Bashkirian (Rodríguez et al. 2013a) and up to the early middle Bashkirian (Fedorowski et al. 2012), and of Spirophyllum up to the middle or late Moscovian ( de Groot 1963;Fedorowski 1970Fedorowski , 2004 has been reported previously, but the remaining two D-F -peels, G -polished surface. For stratigraphic position see text. ...
... Dibunophyllum, typical of the late Viséan (Brigantian), extends into Serpukhovian strata in several areas including the Donets Basin [e.g., Hill 1938Hill -1941Vassilyuk 1960Vassilyuk , 1964 (Cózar et al. 2014) or insufficiently known except for those described by Rodríguez et al. (2013a) from the early Bashkirian of Morocco. The single, incomplete corallite from the d'Hassi Kerma Formation (Algeria), described by Semenoff-Tian-Chansky (1974, p. 97, pl. ...
Article
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Seven genera (one new), belonging to four subfamilies, seven named species (six new), four species left in open nomenclature and two specimens included in this paper as unnamed Aulophyllidae are described from strata ranging from the lowermost Bashkirian Limestone D5¹⁰ to the lower Bashkirian Limestone F1. A new genus: Voragoaxum and six new species: Dibunophyllum medium, Dibunophylloides columnatus, D. paulus, D. similis, Voragoaxum cavum and Rozkowskia lenta are introduced. Comparison of the ontogeny of the earliest Bashkirian species of Nina Fedorowski, 2017a and Dibunophylloides Fomichev, 1953 suggest the derivation by descent of the Family Bothrophyllidae from the Subfamily Dibunophyllinae. This means that true bothrophylla are absent in the Mississippian strata of the Western European Province and, perhaps, in the contemporaneous strata of other areas as well.
... However, recent studies revealed that several rugose coral species survived to Carboniferous glaciation event due to the persistence of warm water ocean currents maintaining tropical conditions on the platform (e.g. Tindouf Basin, Morocco-Algeria; Fedorowski et al., 2012;Rodríguez et al., 2013;Somerville et al., 2013;Cózar et al., 2014). Despite the lack of contemporaneous extended coral reefs elsewhere, it cannot be excluded that the Tianlin area provided an ecological refuge for corals, related to oceanic currents. ...
Article
Metazoan reef building receded globally during the Carboniferous after the Late Devonian extinction events. Shallow-water bioconstructions were generally small and scarce, and corals played a minor role in their construction. However, in southern China, one large (50 m high) and three small (6–16 m high) coral reefs, dating from the Late Viséan–Serpukhovian, have recently been discovered in two localities in Guangxi. To understand the occurrence of these coral reefs and to constrain the factors that controlled their growth, three sections around Langping (Guangxi) were measured, and selected samples were analysed using petrography, biostratigraphy, and chemostratigraphy. The depositional environment of these exceptional Mississippian reefs was interpreted as a low angle platform (1–2.5°), recording oligotrophic conditions and normal salinity. The three small reefs have grown around the fair-weather wave-base, whereas the large coral reef has grown in a deeper environment, between the fair-weather and storm wave-base. During Carboniferous, the global temporal reef distribution can be partly ascribed to paleoclimate changes. However, in southern China, the growth of extended Mississippian coral reefs is restricted to a short time window, the Late Viséan-Serpukhovian, which coincides with high amplitude and high frequency sea-level fluctuations most likely related to glacial pulses. Recent studies revealed that several rugose coral species survived the mid Carboniferous glaciation event thanks to the persistence of warm water ocean currents maintaining tropical conditions on the platform. Due to the scarcity of extended coral reefs elsewhere, it cannot be excluded that Tianlin provided an ecological refuge for corals, related to oceanic currents. Another potential favorable factor could be the mid ramp depositional setting. The deep-water platform areas could potentially provide more stable conditions, less affected by global stress events. However, the ‘deep reef refugia’ hypothesis remains debatable as only very few studies have explored its validity at the community level. Even if the causes of the occurrence of an extended coral reef in southern China cannot be fully constrained, the existence of this large coral framework in the Late Viséan-Serpukhovian provides additional evidence that coral communities did build reefs after the Late Devonian extinction events.
... DV). Serpukhovian and Bashkirian are known in the Tindouf Basin Rodríguez et al., 2013;Cózar et al., 2014). The Moscovian fusulinid faunas of Bechar Basin (Algeria) (e.g., Sebbar, 2000) are not known in the Jerada Basin. ...
Book
The sedimentology, biostratigraphy, and sequence stratigraphy of the Early Carboniferous turbiditic basins of Moroccan Meseta are described in this book. After numerous lithologic and paleontologic investigations, a precise biostratigraphic scale was built, especially by foraminifers for Morocco to date limestones in platform, but also turbidites because carbonate and detrital sediments are mixed in platform and basin. These basins were formed in a structural context of transtension from Famennian to Visean and transpression during late Visean and Namurian with the formation of glidding and tectonic nappes. Four marine basins more or less connected together, existed in this period: (1) Sidi Bettach near Rabat, (2) Central Morocco between Oulmes, Azrou and Khenifra, (3) Jebilet and High-Atlas near Marrakech, and (4) Eastern Meseta basins between Fès and Oujda. The tectonic control probably stronger than eustacy produced second order, third order and fourth order sequences that differ from Vail’s sequences in the basins. As exemplified by the Sidi Bettach Basin, the opening of basin began by a tectonic activity on faults that produced olistolites, conglomerates, slumps and sandy turbiditic fan in the basin. Then, sandy turbidites fans and sandy-clayey turbiditic fans retrograded and prograded in order to fill the basin. In period of tectonic relaxation, sharp regression can be observed in Sidi Bettach Basin. Similarly, shelf and deltaic deposits filled completely the basin in Central Morocco, Jebilet and High-Atlas basins before the glidding of nappes and olistolites in platform and basin during late Viséan and Serpukhovian. On mixed carbonate and detrital platforms surrounding the basins or on horsts within the basins, the eustacy prevails upon the tectonics, and consequently sequences are more similar to the Vail’s type. Comparisons between Moroccan sequences of platforms and basins, and sequences of platforms in Belgium and Great Britain show that some discontinuities are coeval. Nevertheless, there are also additional sequences that could be due to the local tectonics. According to their palaeobiogeographical affinities, it is possible to deduce that the Moroccan basins were connected eastwards with Palaeo-Tethys and northwards with European Culm basin of the Rheno-Hercynian zone through South Portuguese zone.
... Moreover, most species are very conservative, remaining unchanged during a long period that may be estimated between 12 and 15 million years. As stated in recent research of areas where the shallow-water carbonate platforms were preserved up to the Bashkirian (Kossovaya, 1996;Fedorowski et al., 2012;Rodríguez et al., 2013b, Cózar et al., 2014, some species such as Palaeosmilia murchisoni Milne-Edwards & Haime, 1848, Palastraea regia (Phillips, 1836), Dibunophyllum bipartitum (McCoy, 1849), remain unchanged and new species from other genera (Actinocyathus D 'Orbigny, 1849, Arachnolasma Grabau, 1922, Gangamophyllum Gorsky, 1938, Axophyllum Milne-Edwards & Haime, 1851, Lithostrotion Fleming, 1828, Diphyphyllum Lonsdale, 1845, Siphonodendron McCoy, 1849 still remain. Adarouch is an excellent example of that, because some of the species recorded in the Serpukhovian reach the Bashkirian (Rodríguez et al., submitted). ...
Article
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The Serpukhovian coral assemblages from Idmarrach and Tirhela formations (Adarouch, Morocco) have been studied. They yielded quite diverse assemblages with a total of 32 rugose and 1 tabulate species. The distribution of corals in the sections Idmarrach 1, 2, 3, and 4 and Tirhela 1 and 2 has been established, which include Serpukhovian and Bashkirian rocks. The Serpukhovian assemblages are composed mostly of species that have their higher abundance in the upper Viséan. However, most of the recorded taxa in Adarouch have been already mentioned in Serpukhovian rocks from Britain, Moscow Basin, Urals, Donets Basin and other North African regions such as Tindouf and Béchar. Thus, their stratigraphic range is not expanded. The coral diversity is mainly concentrated in biostromes from the Idmarrach 1 section. However, the high total diversity is due to the combination of favourable depositional settings and a mixture in different beds of several ecological environments, such as coral shoals, protected lagoons and microbial mounds. Most Serpukhovian species have been recorded in areas from the western Palaeotethys previously mentioned. The total assemblage can be considered as typical for the late Mississippian in the western Palaeotethys. However, a small degree of isolation is registered by the absence in the Serpukhovian from Adarouch of the genera Lonsdaleia, Actinocyathus, Tizraia and Kizilia that have been recorded in other North African basins. That fact may be explained by the incipient rising of some areas as ‘highs’ due to the start of the collision between Gondwana and Laurasia.
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In the Qoltag tectonic belt of eastern Tianshan, southwestern Central Asian Orogenic Belt, there are widespread Carboniferous marine volcanic-sedimentary successions. These successions record critical information about the development of the North Tianshan Ocean. To date, ages of them are uncertain, due to the lack of index fossils. In this study, abundant rugose corals, fusulines, and some conodonts are collected and allow us to assign precise ages for the successions. In ascending order, we recognized four rugose coral assemblages, including the Zaphrentites-Meniscophyllum Assemblage, Gangamophyllum-Palaeosmilia-Kueichouphyllum Assemblage, Petalaxis-Koninckophyllum Assemblage and the Ivanovia Assemblage. Four fusuline zones, including the Profusulinella parva-Profusulinella staffellaeformis Zone, Profusulinella wangyui-Eofusulina triangula Zone, Fusulinella-Fusulinella Zone and the Rauserites rossicus Zone were also established. Based on these new fossil assemblages and biozones, age of the sedimentary units in the Qoltag tectonic belt was constrained as following. The Nanbeidagou Formation ranges from Tournaisian to early Viséan in age, the Yamansu Formation from early Viséan to late Bashkirian, the Shaquanzi Formation from late Bashkirian to middle Moscovian, the Dikaner Formation from Bashkirian to Moscovian, and the Qi’eshan Formation from Bashkirian to as late as early Gzhelian. The updated Carboniferous framework enables the establishment of regional standard and improves the precision of correlation with others. It further provides a sound basis for the future interpretation of tectonic evolution in the southwestern Central Asian Orogenic Belt.
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